When I click in my browser (Firefox 1.5.0.6) on back button it never brings me to the part of the site I was before but to the top of it.. On other sites it works..

By "part of the site" you mean the position of the page ? I do not know why, but on OVH the PHP pages are not cached. I still haven't find a solution

yeah the position on the site - it is quite useful for example when reading all comments pages and after clicking on some particular vehicle and back it came to the top of the site with all comments... same when clicking on the vehicle on some huge site (Knight Rider) - you must again scroll down on the position where you were before...

On IMCDb I always open new tabs/pages for vehicle links, it is much easier than having to go back each time.

Yeah, same here. It's tabs for me since that returning to top thing got annoying.